It is known in the prior art for components, in particular motor vehicle components, to be produced by sheet-metal forming. To this end, a sheet-metal blank is provided, this in most instances being a sheet-steel blank. Light-metal materials such as, for example, aluminum alloys or similar, can also be used.
To this end, the respective sheet-metal blank is formed to a three-dimensionally shaped sheet-metal formed component between an upper tool and a lower tool. Such sheet-metal components in most instances have a shell-shaped configuration.
In order for hollow components, in particular hollow components that are closed in the cross section, to now be produced by means of sheet-metal forming methods, U-to-O forming is known from the prior art. To this end, a sheet-metal blank is likewise first provided. This sheet-metal blank is formed in such a manner that said sheet-metal blank has a U-shaped configuration in the cross section. In a subsequent forming step, the outwardly directed or projecting, respectively, legs of the U-shape are then further formed so as to generate a cross-sectional O-shape, consequently a hollow profile that is closed in the cross section.
U-shapes and O-shapes in the context of the invention does not mean that a cross-sectional U and an O have to be necessarily adhered to. U-shaped is to be interpreted in such a wide manner that a hollow profile that is unilaterally open is produced, and O-shaped to be interpreted in such a wide manner that a hollow profile that is closed in the cross section is produced, the latter as opposed to the letter O however also potentially having other closed geometries.
In order for cross sections that are mutually dissimilar across the longitudinal profile to now be able to be formed, in the case of O-shapes mandrels are driven into particularly the end side of the hollow component to be produced and withdrawn upon completion of the forming procedure.
A forming tool in which the end-side plug-in mandrels in conjunction with a U-to-O forming procedure can also be configured in segments is known from DE 10 2011 051 965 A1, for example.